Uncrewed Systems Technology 046

34 Dossier | IAC AV-21 drive. Its CPU is a 12-core Intel Xeon for up to 24 GHz clock speed, and sufficient space for 32-512 Gbytes of RAM. It features two USB 3.0 ports, two for USB 2.0, four for 10 Gbyte Ethernet and another four for 1 Gbyte Ethernet , with several additional multi-I/O channels and one for audio, covering the gamut of sensor data feeds needed to qualify as an autonomous driving computer. It also comes with slots for CAN FD, as well as interfaces for the different Ethernets’, raw data, and additional GPUs or FPGAs as hardware accelerators. And for surviving high speeds and vibrations, the system is tested to the EN 60068-2-6, EN 60068-2-27 and EN 60068-2-64 standards for shock and vibration. It is sized at 330 x 376 x 156 mm and functions on 10-30 V supply inputs. Also, the GPU is an Nvidia Quadro RTX 8000 with 4608 cores, 96 ROPs and 48 Gbytes of onboard memory. “Outside of the main computer, on the low-level controllers’ side, we made a number of operational changes that helped our teams in two key ways,” says Andrew Keats, technical operations manager at the IAC. “One was to speed up their turnover of the car, because normally you have to shut the whole thing down and bring it back up between updates, but with our controller changes that’s no longer the case. The other was that they now get so much more data from the engine control unit and its lower level sensors that they didn’t have before.” Mitchell adds, “That turnover improvement was also critical because we have way more practice days than most motorsport – at least 10-20 track days per team – and renting the track plays hell with teams’ budgets, so maximising uptime is everything to them.” As for Schaeffler Paravan’s Space Drive drive-by-wire system, it is triple- redundant and supplies peaks of 60 A per motor controlled (30 A continuous), with a cycle time of 10 ms. As well as having two CAN bus interfaces, two FlexRay ports and two LIN bus interfaces, it also has a DTC connector for automotive diagnostics and eight digital I/Os, two of which have timer functions. According to Dr Prucka, “These systems incorporate a separate electrical circuit and several levels of redundant sensing to make sure the vehicle will stop in case the autonomous systems fail or the vehicle loses communication with race control.” Connectivity and comms Also key to control is New Eagle’s Raptor software platform, which Keats explains is vital to both safety and general operation of the full system. “It includes and controls a switch that has several stages to power-up different levels of the system,” he says. “It also has a program on the back end where race control goes through to access the car, which is quite standard for a lot of racetracks.” Dr Prucka adds, “The New Eagle system continuously checks that all the other electronics are communicating, and it can take over control to perform an emergency shutdown if the vehicle loses contact with the autonomous computing system.” The main transceiver on the car is Cisco’s URWB (ultra-reliable wireless backhaul) FM4500 MOBI, which transmits and receives at 5.1 to 5.8 GHz as well as at 4.9 GHz with OFDM modulation. It is built around an 880 MHz CPU, a 2 x 2 MIMO array and two Ethernet ports, and supports roaming connectivity on vehicles moving at up to 225 mph. Of the URWB’s selection, Keats notes, “We went with that partly to have our own fine control over the network. The problem with 5G right now is that consumer-grade systems aren’t that reliable, and industry-grade is still prohibitively expensive, but the FM4500’s fluid mesh allows us great flexibility with the stationary infrastructure we set up at the track to enable constant telemetry between the cars and the teams.” Mitchell adds, “It’s an ultra-low latency wi-fi system, which can even be used for vehicle-to-vehicle comms. That can be important in some approaches to road autonomy, although we have yet to go with a high data load configuration for things like live video streaming. Small data packets are all we need for control and data telemetry. “We’ve tried different 5G systems, but we found that performing smooth hand- offs between our antenna towers was a real challenge with 5G. So the Cisco system works great for now.” Powertrain and drive The drivetrain has received the most attention throughout the IAC’s technology refresh in the lead-up to the next race. October/November 2022 | Uncrewed Systems Technology While a dSpace Autera is used as the main computer, a Motec ECU handles throttle and shifting, and a Space Drive from Schaeffler Paravan brakes and steers by wire (Courtesy of Clemson University)